I found a picture showing the transmission by two heterozygous alpha thalassemia trait asian (cis-deletion) parents, and modified it to also show the inheritance by two heterozygous alpha thalassemia african (trans-deletion) parents. Here you go: https://drive.google.com/open?id=1HQU1VuhI4Jc9WJR2POwnTq9T8wEdv7dw
Dr.Goljan explains it really well on the audio. I will just give the basic idea. All the hemoglobins have alpha in it therefore you cannot notice it on hemoglobin electrophoresis
bc the parents are asian, they are cis deletion carriers. So their kid can either be a cis carrier or have Hb Barts, its not possible to get HbH
Easy pictures to understand
In what situations will HbH be formed (3 alpha chain deletions)?
in ß Thalassemia there is HbA2 increase and HbA decreases, even in ß+
, normal electrophoresis rules this out. same for A)-C)